5 JSON Schemas That Stop AI Coding Agents From Shipping Garbage

Your agent said "done". Production disagreed.

If you run autonomous coding agents (Cursor, Claude Code, Windsurf, custom loops), you have met the silent failure mode: the agent returns plausible output, the pipeline accepts it, and the breakage surfaces three steps downstream.

The fix is not a smarter model. It is deterministic contracts at every handoff. Below are the 5 JSON Schemas I now require in every agent pipeline.

1. Task Handoff Schema

Every task between agents carries: id, goal, inputs[], acceptance_criteria[], max_turns. If an agent cannot produce acceptance_criteria, it is not allowed to start.

2. Tool-Call Envelope

Wrap every tool call as {tool, args, expected_shape, on_failure}. expected_shape is validated before the result re-enters the agent context, so a malformed API response never poisons reasoning.

3. Code-Evaluation Result

{status: pass|fail, tests_run, tests_passed, error_excerpt}. No free-text "looks good". A pipeline that cannot count tests cannot trust a claim.

4. Review Verdict

{verdict: approve|request_changes, blocking_issues[], nits[]}. Splitting blocking from non-blocking stops the classic loop where an agent blocks a PR over a typo.

5. Artifact Manifest

{files[], hash, produced_by, verified_by}. Determinism lives here: if the hash is not in the manifest, it did not ship.

Why this works

Schemas move failure detection left — from a 2 a.m. incident to a validation error at the boundary. They are boring, versionable, and model-agnostic: swap GPT for Claude and the contracts still hold.

I packaged these 5 schemas (plus a Pydantic V2 validation CLI and cross-platform configs for Cursor/Windsurf/Claude Code) into a drop-in vault:

-> Universal Agent Skills & Production Prompt Vault 2026 — 50% OFF with code LAUNCH50
https://ancuboy.gumroad.com/l/universal-agent-skills-vault/LAUNCH50

Deploy contracts that hold. Stop fixing broken agent runs by hand.

Built by a solo engineer shipping deterministic automation tools.